Fix old emails on push integrations

We added a new branches_to_be_notified property and old integrations
were not working because these defaulted to nil

app/models/project_services/emails_on_push_service.rb

@@ -25,10 +25,9 @@ class EmailsOnPushService < Service
   end
 
   def initialize_properties
-    if properties.nil?
-      self.properties = {}
-      self.branches_to_be_notified ||= "all"
-    end
+    super
+
+    self.branches_to_be_notified = 'all' if branches_to_be_notified.nil?
   end
 
   def execute(push_data)

changelogs/unreleased/198577-fix-emails-on-push.yml

+---
+title: Fix emails on push integrations created before 12.7
+merge_request: 23699
+author:
+type: fixed

spec/models/project_services/emails_on_push_service_spec.rb

@@ -21,6 +21,22 @@ describe EmailsOnPushService do
     end
   end
 
+  context 'when properties is missing branches_to_be_notified' do
+    subject { described_class.new(properties: {}) }
+
+    it 'sets the default value to all' do
+      expect(subject.branches_to_be_notified).to eq('all')
+    end
+  end
+
+  context 'when branches_to_be_notified is already set' do
+    subject { described_class.new(properties: { branches_to_be_notified: 'protected' }) }
+
+    it 'does not overwrite it with the default value' do
+      expect(subject.branches_to_be_notified).to eq('protected')
+    end
+  end
+
   context 'project emails' do
     let(:push_data) { { object_kind: 'push' } }
     let(:project)   { create(:project, :repository) }

spec/requests/api/services_spec.rb

@@ -127,21 +127,6 @@ describe API::Services do
         expect(json_response['properties'].keys).to match_array(service_instance.api_field_names)
       end
 
-      it "returns empty hash or nil values if properties and data fields are empty" do
-        # deprecated services are not valid for update
-        initialized_service.update_attribute(:properties, {})
-
-        if initialized_service.data_fields_present?
-          initialized_service.data_fields.destroy
-          initialized_service.reload
-        end
-
-        get api("/projects/#{project.id}/services/#{dashed_service}", user)
-
-        expect(response).to have_gitlab_http_status(200)
-        expect(json_response['properties'].values.compact).to be_empty
-      end
-
       it "returns error when authenticated but not a project owner" do
         project.add_developer(user2)
         get api("/projects/#{project.id}/services/#{dashed_service}", user2)